Checking the exhaust fan
An exhaust fan is used to direct smoke, fume and toxic chemicals out of house and chimney. Other exhaust fans will also redirect hot air back into the home for more efficiency. Checking if the exhaust fan works is easy.rclma You just have to start a fire in the fireplace and turn the exhaust fan on. If the smoke goes up the chimney and you hear the fan working, then everything is alright. If the smoke begins to enter the house, this means that the fan is faulty. When it comes to exhaust fans that allow hot air to enter the home, checking if they work is even easier. Just turn the fan on and if you notice air coming in through the vents, then the fan is working properly. If not, than it needs repairing.